<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>
<script src="../js/vue.js"></script>
<div id="app">
  <h2 v-if="isShow">{{message}}</h2>
  <h2 v-else>v-else这里展示</h2>
</div>
<script>
    const app = new Vue({
        el:'#app',
        data:{
            message:'hello vue',
          isShow: true
        }

    })
</script>

</body>
</html>